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PMID: 2988513 Published · ppublish English Journal Article

Molecular modelling of human complement subcomponent C1q and its complex with C1r2C1s2 derived from neutron-scattering curves and hydrodynamic properties.

The Biochemical journal ·Vol. 228 ·No. 1 ·1985-05-15 ·Pages 13-26

Perkins SJ

Abstract

Models for the structures of subcomponent C1q of first component C1 of human complement and its complex with subunit C1r2C1s2 are compared with experimental neutron-scattering curves. The length of the C1q collagenous arm is closer to 14.5 nm than to 11.5 nm proposed from electron microscopy, and this is consistent with the primary sequence of C1q. The mean C1q base-arm angle is 40-45 degrees and C1q is found to be flexible: the base-arm angle can vary up to 30 degrees from equilibrium at any moment. The complex of C1r2C1s2 and C1q requires a large shape change in C1r2C1s2. Ring-like models for C1r2C1s2 are not as successful at rationalizing the scattering data as are models that involve C1r2C1s2 binding to one side of C1q. Hydrodynamic calculations of the sedimentation coefficients for C1q and C1 are generally consistent with these neutron models.

MeSH Terms
Complement Activating Enzymes Complement C1 Complement C1q Complement C1r Complement C1s Computers Humans Macromolecular Substances Models, Molecular Neutrons Protein Conformation Scattering, Radiation
Chemicals
Complement C1 Macromolecular Substances Complement C1q Complement Activating Enzymes Complement C1r Complement C1s
Authors & Affiliations
1 authors, click to expand affiliations / ORCID
Perkins S J
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47 references, click to expand
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Article Info
Journal
The Biochemical journal
Abbr.
Biochem J
ISSN
0264-6021
DOI
10.1042/bj2280013
Published
1985-05-15
Pages
13-26
Language
English
Region
England
NLM ID
2984726R
PMCID
PMC1144948
Subset
IM
External Links
PubMed source DOI: 10.1042/bj2280013 PMC Full Text View journal details
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